The present invention relates generally to crop harvesting machines commonly referred to as disc mower-conditioners and, more particularly, to a disc cutterbar configuration that permits the utilization of a drive belt to transfer rotational power between the respective disc cutters.
Typically, disc cutterbars used on implements such as disc mower-conditioners include a transmission casing mounting a plurality of disc cutters rotatable about an upright axis of rotation along the transverse width thereof. Each disc cutter is provided with a drive gear meshed with adjacent idler gears so as to form a power transmission train to transfer rotational power between all disc cutters. This gear driven drive train is expensive to manufacture and to maintain as it requires an oil tight transmission casing to encapsulate an oil bath for precision intermeshing gears.
Gear driven disc cutterbars further suffer from an inherent high level of noise during operation due to the intermeshing gear teeth. Succeptability to damage is also a significant problem with gear driven disc cutterbars because of the precise nature of the operation thereof. Any damage to a drive gear within the enclosed transmission casing normally results in additional damage to adjacent gears. Also, a required amount of lubrication is needed to be maintained within the oil tight transmission casing to dissipate the heat generated by the operation of the meshed gears and to provide sufficient lubrication therefor.
Attempts to provide a belt driven disc cutterbar have been made in the past; however, slippage between the driving power transmission belt and the engaged sheave creates interference problems between the rotating knives on adjacent discs as the path of rotation of the adjacent knives must overlap to prevent areas of uncut crop material between discs. One solution to this problem is to place the path of rotation of the respective adjacent rotating knives in different planes, such as seen in U.S. Pat. No. 3,138,911 and in U.S. Pat. No. 3,457,714. Such solutions provide an r unacceptable scallop-shaped cut compared to the uniform level of cut obtained from the gear driven disc cutterbar.
Accordingly, it would be desirable to provide a belt driven disc cutterbar whose operation and performance would at least approximate conventional gear driven disc cutterbars.